#include #include const int N = 1000005; int n, q, a[N], pre[N]; // Helpers void read(int &); // Segment Tree int cnt, root[N]; int build(int, int); int insert(int, int, int, int, int); int query(int, int, int, int); int main() { read(n); for (int i = 1; i <= n; i++) { read(a[i]); } root[0] = build(1, n); for (int i = 1; i <= n; i++) { if (!pre[a[i]]) { root[i] = insert(root[i - 1], 1, n, i, 1); } else { int tmp = insert(root[i - 1], 1, n, pre[a[i]], -1); root[i] = insert(tmp, 1, n, i, 1); } pre[a[i]] = i; } read(q); while (q--) { int l, r; read(l), read(r); printf("%d\n", query(root[r], 1, n, l)); } return 0; } // === Helpers === void read(int &x) { x = 0; char ch = getchar(); while (!isdigit(ch)) ch = getchar(); while (isdigit(ch)) { x = x * 10 + ch - '0'; ch = getchar(); } } // === Segment Tree === struct node { int l, r, c; } tr[N << 6]; inline void pushup(int u) { tr[u].c = tr[tr[u].l].c + tr[tr[u].r].c; } int build(int l, int r) { int p = ++cnt; if (l == r) return p; int mid = l + r >> 1; tr[p].l = build(l, mid); tr[p].r = build(mid + 1, r); return p; } int insert(int p, int l, int r, int x, int v) { int q = ++cnt; tr[q] = tr[p]; if (l == r) { tr[q].c += v; return q; } int mid = l + r >> 1; if (x <= mid) { tr[q].l = insert(tr[p].l, l, mid, x, v); } else { tr[q].r = insert(tr[p].r, mid + 1, r, x, v); } pushup(q); return q; } int query(int u, int l, int r, int x) { if (l == r) return tr[u].c; int mid = l + r >> 1; if (x <= mid) return tr[tr[u].r].c + query(tr[u].l, l, mid, x); return query(tr[u].r, mid + 1, r, x); }